Blast from the Past

Naval Evolution & The Affondatore

Welcome to ‘A Blast from the Past’ our weekly feature where we take a look at defence products from the past. Be they big or small anything is on the table for our consideration. Today we bring you, ‘The Affondatore’ – an Italian Ironclad vessel dating from 1866. The vessel was part of a new wave of ship designs provoked by a revolution in naval technology. The revolution saw the transition from sail powered vessels, to mechanically driven vehicles. Its construction represented the culmination of over fifty years of organic maritime developments in propulsion, weaponry, and armour.

The coal fired boiler would be the centrifugal force for the propulsion revolution. Whose climax would see the ancient sail fade into insignificance, and for Italy the construction of the Affondatore. The propulsion system which would replace it relied on an axel, fixed to a cylindrical tube, attached to a boiler at one end and an engine on the other. The engine contains a series of pistons, which processes steam from the boiler and filters it into chambers. The chambers are subject to the constant down-up motion of the pistons, driven by the power of the steam which forces each piston head down. The pistons are then attached to the axel which moves in a circular manner, following each chamber pressurization. The axel terminates with a propeller which then protrudes from a vessel’s rear. The steam powered circular motion of the axel courtesy of the engine, then allows the propeller to start its submerged cycle. A low pressure zone behind the propeller is then created, via the device’s spinning procedure. The high pressure water which makes up the underwater environment, flows towards the low pressure space behind the propeller assembly – seeking to escape the high pressure. When it does so it becomes trapped before Newton’s Third Law (Each action produces an equal and opposite reaction) operates on the water and expels it in the opposite direction it came in i.e. out the back. Thrust is then generated and the boat moves. Platforms relying on the boiler-steam-engine-axel-propeller system are termed ‘screw ships’. A field which was populated exclusively by mono-propeller designs until the dawn of the 20th century.

The lesson learned by European advisers was that the return of the ram on the 19th century battlefield was possible

The innovation in weaponry which would eventually allow the Affondatore’s construction came courtesy of the American Civil War (1861 – 1865). A struggle whose maritime sphere, created the impetus for a revolt against the established assumptions around marine weaponry via the battles of Hampton Roads and Mobile Bay. Hampton Roads, fought off the Virginian coast on the 8th of March 1862 saw a Confederate, iron armoured ship held its own against a plethora of wooden vessels. This demonstrated the superiority metal armour at defeating traditional round shot. Two years later, in the summer of 1864, another Confederate armoured ship ‘Tennessee’ took on many Union vessels by ramming them. The lesson learned by European advisers was that the return of the ram on the 19th century battlefield was possible, Tennessee though had also been sunk by flank fire from other vessels. The development of a new type of omni-directional turret was thought to be needed, to allow ramming to be utilized but without the fear of being unable to fire while doing so. The consequence would be the development of the casemate design. A remarkable departure from the broadside concept which had dominated naval warfare for centuries. Instead of rows of guns on either side of the ship, the casemate would see fewer turrets encased in steel boxes. The boxes would then be placed on the deck, instead of the interior and would ideally rotate giving a 360 degree firing radius.

The third component, required for the Affondatore’s production would reside in armour advances. the prerequisite improvements in armour came about via the Crimean War (1853 – 56), where it was observed at the otherwise fruitless Battle of Kinburn that iron armoured ships could be invulnerable to contemporary weaponry. During the battle, the French Navy utilized steam propelled fortresses, that pounded Russian fortresses into submission – without yielding once to enemy counterfire. The potency of metal armour, led to compelling proof for the potential of fully mobile armoured battleships. The French Navy was keen to push this idea of metal armour, to its limits and on the 1st of January 1857 the Breton engineer Henri Dupuy de Lome agreed the directorship for the French Navy’s construction office. He was acutely aware that the French shipyards could not supply what was desired, instead opting to use them to develop wrought iron. Their work on the iron alloy, then allowed for the fabrication of ship armour – through improving on the wrought iron’s properties. The armouring process eventually saw enhanced wrought iron fashioned into plates and attached to the sides of wooden warships. The climax for French developments in armour came in 1859 with the launch of La Glorie which encompassed these visionary steps. By the close of the American Civil War, propulsion, armament and armour had reached a point where it could be put together to make a wholly new form of warship.

In 1860 the Savoyard Kings of Sardinia-Piedmont and future kings of a united Italy, decided they wanted to be part of the nautical revolution. Like the French though, the Italian naval elites understood that their yards could not produce ground-breaking ships. In that same year, the vessel which would become the Affondatore was ordered not from a Genovese shipyard, but from London’s Millwall Iron Works, Ship Building & Graving Docks Company Ltd. based in Millwall. The company was astonishingly well staffed. Its founder, the Stafford born shipbuilder Charles John Mare had previously been a shipwright manufacturing iron based ships in Deptford. His history with the maritime industry was wide ranging, and he was viewed favourably by most in the industry. Underneath Mare, overseeing the yard’s day to day activities was an even more capable individual – John James Hughes. A Welsh engineer of remarkable vigour who, in an extraordinary turn of events would one day found the Ukrainian city of Donetsk. He had already made waves in the nautical industry, working for Wales’ Uskside Foundary where he had invented multiple concepts, in the fields of both naval armaments and armour. The company was founded in parallel with a similarly open-minded firm in England’s north on the River Tyne, where William Armstrong – an armaments entrepreneur had opened up his arsenal. The manufactory he established, Elswick Ordnance Company pumped out a particularly progressive, weapon which utilized the hitherto underdeveloped breech loading method. The arm for which he was famous, had been the Armstrong Gun which was invented in 1854. The eponymous artillery piece he developed consisted of a pressurized carbon steel tube, resting on pressure enhancing thick wrought iron springs. The tube was then mounted on a body via the use of trunnion rings. The artillery was loaded via, a screw system unlocking the back of the tube creating an access space to the central tube. The ammunition was then placed inside ready for firing. By disposing with muzzle loading, the gun was made both safer and quicker for reloading.

The weapon’s interesting features did not end simply at its loading procedure however. The gun also utilized a new form of ammunition – the cast iron shell. When ready to fire, the Armstrong gun would fire its shells through a 38 groove rifled interior. A thin lead layer on the outside of the cast iron shell would serve to cling unto the 38 grooves. The tight fit sealed the chamber absolutely, allowing a firmly ensconced cavity to exist between the shell and the gunpowder charge below it. When the artillery piece was ready to fire, it would do so via igniting the gunpowder charge unleashing hot gas. The gas collected behind the round locked in due to the total blockage presented by the lead lined shell. Eventually the build up of gas is too much to contain and the shell is fired outward. Because the cavity between charge and round is so totally secured, compared to the haphazard gas sealing of the cannon ball, more pressure is needed to expel it. The more pressure pre-launch the faster the projectile and as such, the Armstrong shell was leagues above the potency of its round shot competitors. The finished warship would see, France’s armoured obsession, Armstrong’s devastating weaponry and the rapidly moving progress on screw propulsion coalesce around one project. When it sailed to fight the Austrians over the rights to the Adriatic sea in July 1866, it would do so with its 220mm Armstrong breech loaders protected in defiant casemates. One at the back and one at the front, ready to defend an iron behemoth, whose designers had also deemed it appropriate to affix her with a bitingly effective ram which protruded from its front intimidating any approaching captain. On the eve of the Battle of Lissa among heavy Croatian waves, the vessel weighed 4,006 tonnes, with a speed of 12 knots, length of 93m and 120mm of wrought iron armour. When battle came, the Italians would lose but the Affondatore would survive to fight another day – as the vanguard of a modern Italian fleet.